Senior Full Stack Engineer

Octopus Energy · United Kingdom

  • Senior
  • Full-time
  • Posted 2026-09-23
  • Confirmed live on 25 September 2026

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Job description

We're making energy fair, clean, and simple for all using technology. 
Octopus Energy started with a bold idea: to build Britain’s first truly digital energy supplier. By combining world-class tech with brilliant humans who care deeply about customers and driving the renewable energy transition, we made it happen and in 2025, we became Britain’s largest energy supplier. 

Octopus Energy Group is a global energy transition collective. 10 businesses working across 4 continents to tackle energy transformation at nearly every front.

And we constantly push to make energy better. Tirelessly campaigning for fair protections for customers. And building innovative technologies that forge a path to a green energy system.

We’re made up of 10,000+ authentic, committed people working around the world on stuff you'd never expect. We're united by a shared goal: to drive the global green energy revolution. Read our Spotlight series to meet some of the team.

We are looking for a Senior Full Stack Engineer (frontend focus) to join our Low Carbon Tech team.

Low Carbon Tech are installing EV Chargers, Solar, Batteries and Heat Pumps into homes to drive the energy transition at pace. As customer demand grows, our goal is to ensure scaling up never means slowing down or compromising on a world-class customer journey for low carbon tech. 

To make that happen, we are building a new, dedicated engineering and product team to completely re-imagine this process - making it fast, transparent, and predictable for our customers from day one. This will be a small multi-disciplinary team who’ll sit within our much bigger low carbon tech team.

You’ll help design and build the platform architecture, data integrations, and automations that eliminate real world friction. If you want to design and build solutions to scale up electrotech in the nation’s homes, this is the mission for you.

We embrace flat hierarchies and an open, agile culture that fosters innovation, flexibility, and creativity. 

We don’t hang our personalities up with our coats and nor should you. At Octopus, we hire great people who get stuff done, all whilst being themselves.

If this sounds exciting, we’d love to chat.

What you'll do
•
Serve as a bridge across our entire stack, building end-to-end capabilities while helping frontend developers get comfortable with backend/infra and vice versa

•
Take full ownership of features end-to-end, delivering reliable, production-ready code with plenty of autonomy

•
Shape the architecture of brand-new projects from scratch while giving our existing codebases the refactoring love they need

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Maintain high frontend standards in AI-assisted workflows by vetting AI outputs, catching edge cases, and protecting long-term code health

•
Communicate technical ideas clearly and concisely, prioritising high-signal context

•
Keep our releases smooth with automated CI/CD workflows and set up production monitoring to track app health

•
Work closely with product managers and designers to find the leanest, most efficient paths to ship value

What you'll have
•
5+ years of experience with our stack (listed below)

•
Experience taking problems, rather than strict guidelines, and developing strong solutions

•
Confidence owning the development cycle (request, requirements gathering, technical proposal, technical execution, deployment and monitoring.)

•
Confidence tackling large-scale tasks individually

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An empathetic approach to delegating work and collaborating with others

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The ability to develop websites that meet strong accessibility guidelines

•
Experience building scalable, performant sites that handle high levels of traffic well

•
Eager to drive cross-functional work spanning frontend, backend, DevOps, and infrastructure.

•
Pragmatic AI mindset, experience with AI Workflows & Tooling: building harnesses, custom agent skills, MCP integrations, token minimisation strategies, etc.

•
Desirable: energy domain knowledge

Our stack
•
React (required)

•
TypeScript (required)

•
Next.js on Vercel (required)

• Backend Python, Django (required)

•
Testing infrastructure (Playwright, vitest, MSW), observability (Datadog, Sentry), CI (Github, CircleCI) (required)

•
GraphQL w/ Tanstack Query (desirable)

•
PostgreSQL, Celery, and asynchronous background processing (desirable)

 
 

Why else you'll love it here
• Wondering what the salary for this role is? Just ask us! On a call with one of our recruiters it's something we always cover as we genuinely want to match your experience with the correct salary. The reason why we don't advertise is because we honestly have a degree of flexibility and would never want salary to be a reason why someone doesn't apply to Octopus - what's more important to us is finding the right octofit!
• Octopus Energy Group is a unique culture. An organisation where people learn, decide, and build quicker. Where people work with autonomy, alongside a wide range of amazing co-owners, on

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